­^¤åºK­n¡G The companies in Taiwan have invested rapidly in Mainland China from 90's. The trend of investment focus on IT industry. There are many capital to flow to China. On the other hand¡Athe problem of China's capital which flow to Taiwan is more and more serious. Under the regulation of WTO , Taiwan must face the problem of capital of China. The study is to research the flow of money in Taiwan and China. Finally it is evaluated the affection from the viewpoint of national security.